Snoring is an inspiratory sound which arises during a person's sleep. Snoring is believed to be generally caused by the narrowing of the nasopharyngeal airway such that turbulent airflow during relaxed breathing vibrates the soft parts of the oropharyngeal passage, such as the soft pallet, the posterior faucial pillars of the tonsils and the uvula. Many causes for the narrowing of the nasal pharyngeal airway, especially during sleep, exist, as noted below.
Snoring afflicts a large segment of the population, and is a condition affecting both sexes of all ages. During wakefulness, a person is typically able to consciously maintain the nasal pharyngeal passageway in an open condition; however, with the onset of sleep, relaxation allows the nasopharyngeal passageway to restrict, and snoring results. It has been estimated that up to 45% of all adults snore occasionally with about 25% being habitual snorers. Snoring increases with age, and it has been observed that about 50% of men and 40% of women are habitual snorers by the age of 60. Lugaresi et al, "Snoring: Pathogenic, Clinical and Therapeutic Aspects", Reported in Principles and Practice of Sleep Medicine (Kryger et al, Editors 1989) at pp. 494-500.
A restricted nasopharyngeal passageway can occur anatomically. For example, in children, this often is caused by obstruction due to enlarged tonsils or adenoids. In adults, it is not unusual for the narrowing to be caused by obesity. Further anatomical narrowing can be simple a matter of genetics with some persons being predisposed towards a smaller nasopharyngeal cross-section. A reduced nasopharyngeal passageway may also be caused by a lack of muscle tone. Other anatomical conditions contributing to the narrowing of the nasal pharyngeal passageway include choanal atresia, chrono polyp, nasal septal deviation, nasal pharyngeal cyst, macroglossia, retrognathia and micrognathia, but these less common. Leung et al, "The ABZzzz's of Snoring", Post Graduate Medicine (Sep. 1, 1992).
Snoring may also be exacerbated by consuming either alcohol or drugs (such as tranquilizers, sleeping pills and antihistamines) prior to bedtime. Smoking can contribute to the incidence of snoring since cigarettes may irritate the mucus membranes of the upper airway causing swelling and increased mucus production.
Heretofore, it has been reported that there is no indication of pharmacologic management of snoring. Douglas, "The Sleep Apnoea/Hypopnoea Syndrome and Snoring", DMJ, Volume 306 (1993); Leung et al, "The ABZzzz's of Snoring", Post Graduate Medicine (Sep. 1, 1992). However, numerous management techniques have been described, depending upon the perceived cause of snoring. None of these treatments have proved completely adequate. Where snoring is caused or exacerbated by nasal allergy or an upper respiratory track infection, these conditions may be treated pharmacologically, but, as noted above, this is not deemed to be a pharmacologic management of the overall snoring condition.
A basic treatment simply involves having the patient sleep in the prone position or on his/her side. Sometimes this is stimulated by sewing a marble or other object into the back of the snorer's clothes. Where the patient is obese, treatment may be a program of weight loss. Along with these treatments, of course, is the recommendation that the patient avoid use of drugs, cigarettes or alcohol prior to bedtime so as to retard the loss of oropharyngeal muscle tone.
Snoring can sometimes be managed by the use of an appliance. One example is a custom-made mouth-piece constructed to move the snorer's lower jaw forwardly, thus opening the airway. Another example is the use of a positive pressure generator and face mask. These machines pump air through a hose and nose/mouth face mask to keep air passages clear. Use of each of thee devices, however, can cause the subject to have less restful sleep.
Another option for treating snoring is found with surgical techniques. In children whose snoring is caused by an enlarge adenoids, and adenoidtotomy is sometimes prescribed. Where tonsils are also enlarged, a tonsillectomy often accompanies surgery to the adenoids. In adults, uvulopalatopharyngoplasty may be recommended for habitual or heavy snorers. Here, the surgeon resects the uvula, the distal portion of the soft pallet, the anterior tonsillar pillars and the redundant lateral pharyngeal wall mucosa. The purpose of such surgery, of course, is to increase the size of the air passageway thereby allowing unobstructed movement of air through the pharynx. Rates of success of the uvulopalatopharyngoplasty are uncertain, with improvement reported to be in a range from 15% to 65%. Douglas, "The Sleep Apnoea/Hypopnoea Syndrome And Snoring", British Medical Journal, 1993, Vol. 306:1057-60. In some instances, surgical repair of a deviated nasal septum has been shown to improve snoring.
Snoring, therefore, remains a serious problem for a large segment of the population. Not only is it a nuisance, but can itself indicate a more serious condition and, due to exhaustion resulting from lack of sleep, can cause other problems. For example, an association between snoring and hypertension has been found, and cardiac arrhythmia has been reported during sleep apnea attacks. Snoring patients with decreased pulmonary function have been shown to suffer from severe apnea. Not only is the risk of cessation of breathing a danger for snoring, lack of oxygen due to an obstructed nasopharyngeal passageway deprives the body of sufficient oxygen so that an oxygen desaturation arises. Lack of oxygen may cause the brain to rouse the sleeper just enough to take a breath without fully awaking. Since this may happen hundreds of times a night, the snorer does not get sufficient sleep. Moreover, being aroused from deep REM sleep on a repetitive basis may increase heart rate and blood pressure. Thus, snoring may increase the risk of heart attack and stroke, as noted above. Further, due to narcolepsy resulting from exhaustion can cause a lack of attention for the snorer during waking hours thus reducing productivity and even causing dangerous situations should the exhausted snorer operate machinery or vehicles.
Accordingly, there has been a long felt need for improved management techniques to reduce or eliminate snoring. Specifically, a long felt need has existed for pharmacologic methodology in treating snoring which is simple and safe to administer. The present invention is directed to such pharmacological management technique.